The structural, vibrational and electronic properties of ReS2 were investigated up to similar to 34 GPa by Raman spectroscopy, AC impedance spectroscopy, atomic force microscopy and high-resolution transmission electron microscopy, combining with first-principle calculations under two different pressure environments. The experimental results showed that ReS2 endured a structural transition at similar to 2.5 GPa both under non-hydrostatic and hydrostatic conditions. We found that a metallization occurred at similar to 27.5 GPa under non-hydrostatic conditions and at similar to 35.4 GPa under hydrostatic conditions. The occurrence of distinct metallization point attributed to the influence of deviatoric stresses, which significantly affected the layered structure and the weak van der Waals interaction for ReS2.